Apparatus for pressing laminated materials



Sept. 8, 1953 Y. H. SMILEY 'APPARATUS FOR PRESSING LAMINATED MATERIALS Filed Nov. 26, 1947 4 2 Sheets-Sheet 1 INVENTOR.

ATTORNEY P 8, 1953 Y. H. SMILEY 2,651,062

APPARATUS FOR PRESSING LAMINATED MATERIALS Filed Nov. 26, 1947 2 Sheets-Sheet 2 ATTORNEY Patented Sept. 8, 1953 APPARATUS FOR PRESSING LAIVIINATED MATERIALS Yale Hertle Smiley, Kitchener, Ontario, Canada, assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application November 26, 1947, Serial No. 788,244.",

This invention relates to an apparatus for pressing plastic laminated materials, such as the parts of rubber footwear containing unvulcanized layers of rubber, or rubber-like compositions, prior to the vulcanization of the assembled article of footwear.

In the manufacture of certain types of rubber footwear, the parts comprising an inner layer of fabric and one or more layers of tacky unvulcanized rubber or rubber composition, are built up on a last to form the assembled article of footwear, which is subsequently vulcanized. During the assembly ofthe parts small pockets of air are sometimes trapped between the layers of the rubber, or between. the inner layer of fabric and the layers of rubbersuperimposed thereon. After the layers of material have been initially assembled on the last they are poorly bonded together and may be separated in places by small air pockets. tus have been used heretofore for pressing the layers together to remove the air and produce an adhesive bond therebetween. The present apparatus is an improvement overtheprior apparatus which has been used for thatpurposew In the apparatus embodied in, the present invention, the article of footwearto be pressed is sealed within a relatively thin, flexible, elastic envelope which may be. made of sheet rubber. Sub-atmospheric pressure is produced within the envelope and its walls are forced into intimate contact with the outer surfaces of the footwear by the differential of pressure between the outside atmospheric pressure and the sub-atmospheric pressure within theenvelope. struction has the following advantages over the prior types of apparatus which has been used to press the tacky unvulcanized layers of rubber contained in the lasted article of footwear: (1)

it reduces the time, labor and skill required in to envelop an article of footwear of the largest size desired to be produced, (3) the sub-atmospheric pressure within the envelope is effective for causing the air pockets between the layers to expand and be removed as a result of such expansion independently of the external pressure of the envelope on the outer surfaces of the article of footwear, (4) the thin envelope conforms closely to the irregularsurfaces of the footwear Several types of appara- Such conand does not bridge the stepped back edges of the layers of rubber, and (5) the impervious envelope causes the outside higher pressure air to press inwardly 'on'the entire outside area of the article of footwear and thus causes all'layers of the parts laminated thereon to bepressed between the higher outside pressure of the air acting on the flexible, elastic, impervious envelope, and the inflexible surface of the last, on which these laminated parts are built, and thus bond all parts together without necessarily subjecting theinterior of the footwear to sub-atmospheric pressure-through the walls of a hollow last.

The invention is further described in reference to the accompanying drawings, in which:

Fig. l is perspective view of the apparatus embodying this invention, in which two pressing envelopes may be formed at different times between one of the two horizontal diaphragms and the vertically. extending diaphragm to enclose an article of footwear which may be placed on either of the horizontal diaphragms as shown by the boot;

Fig. 2 is a cross-section of the joint between the pressing envelope diaphragms taken on line 2-2 of Figu e 1;

Fig. 3 is a cross-section of --a boot being pressed by the pressing envelope formed by the upper and one of the lower diaphragms and enclosing the boot; and I Fig. 4 is a cross-section of the valve mechanism for controlling the exhaust of air from and the admission of *air to the pressing envelope, and which is taken on line 1-6 of Fig. 1.

An apparatus embodying this invention is shown in Fig.1 of the drawings. It comprises a table [0 having two diaphragms II and I2 stretched across its top frame I3, which is provided with crossmembers i l, over which the lineof division l5 between the diaphragms is formed. The diaphragms ll and'l2 are formed of relatively thin flexible elastic rubber or rubber-like composition, and each of them is adapted to support an article of rubber footwear l6 containingexterior layers I! of tacky plastic unvulcanized rubber and an inner layer iii of fabric lining material (Fig. 3), which are builtup on a lastl9. The article of footwear shown herein is a rubber boot, and is adapted to be enclosed in a pressing envelope 20 (Fig. 3) which may be formed by pivoting an upper diaphragm 2i over the boot I 6 supported by the diaphragm I l. The diaphragm 2| is similar to the diaphragms II and I 2, and stretched in a frame 22, which may be pivoted from its vertical position in Fig. 1 to a horizontal position over the diaphragm I2 to form another pressing envelope around a boot which may be supported on the diaphragm I2.

Since the envelopes formed by superimposing the pivotal Tdiaphragm 5:2 I over 1 either the :diaphragmsII or I2 aresubstafltilllypf the same construction and they operate in the same manner for pressing the boot I6, only one of the pressing envelopes in its pressing positi-omaround the boot is shown, as in Fig. 3, and will beide-r scribed in detail as to its operation on the boot.

When the envelope issoformed,'ithei-boot I6 may be pressed by exhaustin'g'the airfrom the envelope through a pipe23, whichmaybe connected through a valvercasingsflirtoea vac-'- uum line 25. The valves in the casing 24 are controlled by a foot pedal 26 which isadapted; to alternately connect the pipe 23 and discon- "nect'it from the *vacuum line"""-arr'd *an atmospheric' port2 1 "Upon connecting theenvelope 20 'tothe vacuum line '2 5,its walls comprisingthe' diaphragms I I and '2 I arepressedinto intimate contaetwith the" outer surfacedf theboot-I6 -asshown =m Fi'g. 3, and the layersof material contained in the boot are subjected toa pressure per square-inch equal to the difierentiarin'pressure *per square inch within the "envelope "'and the no'rmal *atmo'sphericpressure per square inchonthe'outsideoi 'theenvelope. The required pressure differential may be produced and retained-over the requiredperiod of time to eliminate air pockets and adequately compact the 1ayers-of material 'to'secure good adhesiontherebetween as may be determined'by the operator. Theenvelope which may" be formed between the" diaphragmsfl Hand 'I2 may be similarly operated 'by alternately'exhau'sting and admitting air *thereto-throu"g1; the

' pipe28, which may" be=alternately connected and disconnected with the vacuumline 2-5 and -=the outsideatmosphere.

Three sides of the diaphragms H and I-Fare secured in the table top 'frame I3 byclamping the outeredges thereof between the outer 'frame members 29 and the inner strips 3|). As shown in Fig. 2,- the four'th sides of the dia-phragms I I their edges betweenthe' cross-members --I 4which are drawn together by the bolts 3I. 'I'he lo'w'er edge-bf the pivoted diaphragm 2 I extend-s betweenthe adjoirling edgesof the dlaphragms I I and I2 and is also" clamped in suoh positionmy the bolts 3 I. The frame ZZ for the diaphragm -2I is supported on brackets- 32 seeuredltothe oppositesides of the'tabletop frame I3, andthe frame 22 is pivoted'on pins 33 in the brackets 32. The pins '33 arearranged in all'gnment with the line I5 for-med bythe-intersectingplanes ot the diaphragm-s II,' I2,"-and 2I. 'I'her-efore the frame 22 and the diaphragm fl' arehinged'on "the same axis. "The frame fi is larger thani the 'area of the top' of the table IIlw-hichit-is adapted "to cover, and when it is pivoted to the'horizontal position over-either of thehbottom diaphragms I I or I2, the outer-margin of one ofthe surtaces of the diaphragm-2 I forms ai-hermetically sealed contact with the outer margin ofithediaphragms I I I or- [2.

The pipes'23kand 2-B are connected to thepressing envelopes by nipples='34; whieh aremonnecte'd to-the pipes and:extendxthrought the.lower=: diaphragms: I Ifandr- I2. if'lhefnipples 34, a-si'shownin .Eig. 3, are provided'iwithiflanges 335.5and': 361between which the diaphragms II and I2 are clamped to form sealed joints around the nipples. The nipples 34 are provided with orifices 31 which open into the pressing envelopes. A protective flange 38 is formed on the nipples 34 above the orifices 31 to provide a rest for the zupperaend 39df' the la'stIll;:to;rest-,-..upon, and "prevent the walls;- of theenvelopes formed by the diaphragms from closing the orifices before the i-o -desired degree of sub-atmospheric pressure is ..-reaehed'.within thaenvelope. Referring to' Fig. 4, the pipe 23 leading from the valve casing 24 to the diaphragm II is con- *nooted to achamber 40 in the valve casing 24, 5 andt'the'pipefisleading from the valve casing to the diaphragm 'I2 is connected to a chamber .-4Itinsthex valve lcasing. The vacuum line 25 is connected to a chamber 42 in the valve casing, which is also provided with atmospheric ports 20 21 and 43. The pipe 23 may be alternately con- *nected anddisconneeted toiandilrrom the vacuum -port 42 by valve- 44,-:andithefpipei2 3 maycbeealternately connected and "disconnected to sand "from the atmOspherie'port- Z Itby valve-'45. iSimi- 25 "lar'ly, the pi-pe 28 may he. alternatelymonneeted and disconnected to andfromathe vaeuumtch-amher 42 by i valve 46, andttherpipexzannaylcbeaal- -ternately connecte'd and disconnectedto-andfrom the atmospheric t-port dii by a'.=valves4l. 1A1] 20f =30 these valves 44 1 to 1 41 eare tcpressed ztoward stheir closed positions by separate ssp'rings48. 'F'I'he -valves are controlledtby the toot pedah'2-Iiswhich -is keyed -to m -shaft! 9, which :extends': intoathe inter-ionof -thecasingifll. :An armafaflfis afiixed '35 to the shait 49 and itnetuatesthe-valves through ='-a linkagez.mechanism :comprisingra link 5 I :1 pivotally v eonnectedito tthe arm demand having at leachend: thereofzrai loss" motion-rorislidab'leaeonnec'tion with' themrmsxzfl of 'T-shape::leversn53, "4o which-are pivotedfzontpins 54- tothevvalvemasing 24 and are adaptedi-toioperate the valves. The -loss 'motion connections aare formed'rsbytthepins ill fixed to thesarms 2521M itheileve'rs- 53, and 'which' are 'slidablel in theislots 56 minthetends'zof "45 the link- 5 I 'Dhe vaeuum: iine yalves144 -46wand theiatmospherie tva'lve i45, 41 iiarevoperatedirespectivei by the; rocking movement of the &arms =5? land 58 rofithex leversi53 ,eand the .loss-:motion conneotion betweenathet ends :of the; link fi leperm its th'e sets of the 'valves 44=aands45pand-i4firand 41 Ito :Lbe :operated. individually, ithat one set :may be operated without :toperating Y the a other. Tension :springs 59 rare connected between the -arms 52 -'.'of sthe E levers 53 and zthe valve :casing -24=larid are .adapted to holdi the atmospherimair i valves:45 iand 411in theimopenhpositiens'against the actioni-of their tsprings- 48zwhentthe pedal l2611is7 initsmormal rhorizontalgposition -that is, 3 its released position at the time it is not ebeing .60 :faoted :upon 1by -the'nperatorafoot. fThe-arms .51 "of the iT-shaped levers 54 2 areenormally."spaced ifromithee'stems 'of'thew-vacuumxl'ine valvesdi-a-nd $46 by the action: of: thesprings==59;-=and thereby i'znormaliypermit the spningsfiB .rofz these waives itoeholdi them in theiriclosed positions. :Thenatcmospheric air valves -=--:and 41 are carried Joy tD-shaped levers fi0;:whicharapivoted onithe valve --easing-.24abyzpins= 6| :and; their opening-removements :are arrested by stops e 62 7011 the casing .70 'whichelimit the upwardzmovement-ioftheuarms.

-Thesprings?59s also. retain the: footpedaldli. normallyv-in a; horizontahpositionas shown in Fig. :1. In. the operation of the "apparatus, "the-lasted aarticle of footwear, such asthe' boot [6, is.place'd :55 won-tone of *7 the bottom diaphragms tor=-example the diaphragm I I, with the upper end of the last I9 resting upon the protecting flange: 38 of the nipple 34. The operator pivots thegframe 22 to a horizontal position over the diaphragm I I so as to form a sealed envelope around the boot I6. Air isthen exhausted from'the envelope 20 formed around the boot I6 by depressing the arm 63 of the foot pedal 26, which rocks the T-shaped lever 54 associated with the valves 44 and 45, and permits the valve 45 to close and opens the vacuum line ,valve 44. Thedifierential of pressure thus formed between the interior and'exterior of the envelope 20 forces its relatively thinelastie and' flexible walls into intimate contact with the outer surface of the boot I6. As shown in cross-section in Fig. 3, the last upon which the boot is built has a cavity 64 extending throughout its length. The upper end 39 of the last I9 has an opening 65 which communicates with the interior of the envelope 20 and the cavity 64. The walls of the cavity are provided with passages 66 which allow air to escape from between the interior walls of the boot I6 and exterior walls of the last l9 under the pressure of the envelope.

While the boot is being pressed in the envelope 20 between the diaphragms 2| and II, another boot is placed upon the diaphragm I2. After the boot I6 on the diaphragm II has been pressed, the arm 63 of the foot pedal 26 is released by the operator and allowed to return to its normal horizontal position. In the normal position, communication between the vacuum line 25 and the envelope 20 formed between the diaphragms 2| and II is cut off by the closure of the valve 44, and atmospheric air pressure is produced within the envelope 2!) by opening the valve 45 and admitting atmospheric air through the port 21. The diaphragm 2| is then pivoted over the boot I6 on the diaphragm I2 to form an envelope around the boot. Air is exhausted from the last formed envelope by depressing the arm 61 of the foot pedal 26 which closes the atmospheric port 43 and opens the vacuum line 25 to the envelope. While the pressing operation is being carried out on the boot resting on the diaphragm I2, the boot I6 resting on the diaphragm I I is replaced by another .boot. After the pressing operation has been completed on the boot resting on the diaphragm I2, the arm 61 of the foot pedal 26 is released, and atmospheric air is thereby admitted to the envelope after its communication with the vacuum line 25 has been cut off. The diaphragm 2| may then be pivoted through approximately 180 over the boot which has been placed on the diaphragm II, and the foregoing cycle of pressing operations may thus be repeated.

It is desirable that the diaphragms II, I2 and 2| forming the respective envelopes around the article of footwear be made very thin, flexible and elastic in order that they may conform as closely as possible to the contour of the irregularly shaped article to be pressed. It is necessary, however, that the envelope have suflicient strength to withstand the differential of pressures between the inner and outer surfaces of the envelope where it is unsupported over small areas, and also to withstand the normal wear during the operation of the apparatus. It has been found in practice that calendered sheet rubber having 600% elongation and a thickness of from .018 to 0.030 inch gives satisfactory results. Diaphragms having a substantially less thickness have too short a life and those having a substantially greater thickness bridge portions ofthe 'surfaces to be pressed where "abrupt changes in surface contour .occur as may be proaimed at the edges of stepped back layers of ruber.- Whilethe present preferred form of the invention has-beendescribed herein, it will be understood that changes in the details thereof may be made without departing from the spirit of the invention, or the scope of the claims appended hereto. I 3

Having; thus described my invention, what I claim and desire to protect by Letters Patentis: v, ,1. An apparatus for pressing plasticsurfaces of'an' article having abrupt changes in its 'surface contou'rysaid apparatus comprising two frames, one of which has an inner periphery adapted to fit over the outer periphery of the other, a thin sheet of impervious highly elastic material having its margin affixed to one of each of said frames and thereby held free from wrinkles during the pressing operation, said sheets being adapted to be superimposed over one another with the larger of said frames extending outwardly beyond the smaller of said frames so as to cause the margins of said sheets to be engaged and form an air-tight chamber between the sheets and about the article to be pressed, and means for subjecting said chamber to sub-atmospheric pressure to force said sheets into intimate contact with any surfaces of the article which may be initially bridged by said sheets due to the abrupt changes in its surface contour said sheets being so thin, flexible and elastic that their margins are drawn together and the parting line therebetween is in close contact with and around said article.

2. An apparatus for pressing the plastic surface of an article of footwear formed of plies of unvulcanized rubber and having abrupt changes in contour, said apparatus comprising two fiat sheet diaphragms of flexible highly elastic rubber having a thickness of from .018 inch to .030 inch, a frame for each of said diaphragms, means for afiixing the margins of said sheet to said frames for holding the sheets in a fixed position free from wrinkles, a pivotal joint pivotally connecting one frame to the other so that the diaphragm in one frame is adapted to be pivoted in respect to and superimposed upon the diaphragm in the other frame to enclose the article of footwear therebetween within an air-tight envelope, means for evacuating air from between said diaphragms and thereby cause the outside atmospheric pressure to force said diaphragms into intimate contact with said article over its entire surface said diaphragms being so thin, flexible and elastic that their margins are drawn together and the parting line therebetween is in close contact with and around said article of footwear.

3. An apparatus for compacting plastic unvulcanized layers of rubber footwear having abrupt changes in its surface contour, said apparatus comprising three thin elastic, impervious, sheet diaphragms, a frame for each of said diaphragms, the edges of each diaphragm being afiixed to its respective frame to maintain the diaphragms free from wrinkles, two of said frames being stationary and having adjoining sides, said third frame being pivoted on the line of said adjoining sides so that the diaphragm therein may be pivotally superimposed over either of the stationary diaphragms and form a sealed envelope around the footwear placed therebetween, means for evacuating air from between 

